For a conventional toilet pan using large water replenishing, such as a big unitary toilet pan, the cistern is set in a low position. When drainage is started and before a toilet pan flush is finished and when the water level is going down so that the inlet valve starts supplying water, water from the inlet valve is flowing through tubes to replenish water to perform rim flushing, i.e., a flush rim, of a toilet pan for flushing and cleaning the toilet. Under the influence of the pressure of water input, the replenishing water speed deviation of the inlet value would be large. Therefore, it is difficult to replenish the toilet pan accurately. When water pressure is low and the volume of replenishing water is small, the ceramics surface of the toilet pan may not be washed cleanly, affecting use quality of the toilet pan. On the other hand, when water pressure is high, it causes water waste.
For traditional large water replenishing models, when drainage is started and before toilet flush is finished, and when the water level is going down to the inlet valve for start supplying water, water is flowing from the inlet valve through tubes to replenish water for performing flush rim of the toilet. By this method, after the toilet cistern is full of water inlet and the inlet valve is closed, the water supply will be stopped flush rim. It will take long time to supply the water for flush rim. When the pressure is over, it will make water waste.
Therefore, a large water replenishing device is invented. The large water replenishing device includes a water storage box with a water inlet and an outlet hole, as well as an overflow tube. The overflow tube is connected to the cistern. During water entering, water from the inlet valve flows into the water storage box through the water inlet. When water level is up the height of the overflow tube, water flows into the cistern through the overflow tube. Until the water level is going up to the required working water level, the inlet valve would stop water entering. When drainage starts, water is drained from the cistern and the water storage box is used to replenish water for performing flush rim. In order to install an anti-siphon mechanism, the water inlet of the water storage box is always set on the top of the water storage box to make difference heights between the water inlet of the water storage box and the bottom end of the water storage box. Consequently, when water is entering, water will make direct impact on the water storage box and makes large inlet noise.